Method and apparatus for making bag using ultrasonic sealing

ABSTRACT

A method and apparatus for making bags or pouches is disclosed. An ultrasonic sealer may be used to form the seals. Sealing patterns may be used to provide a desired strength profile.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of, and claims the benefit of the filing date of,U.S. patent application Ser. No. 16/150,751, filed on Oct. 3, 2018;which is a continuation of, and claims the benefit of the filing dateof, U.S. patent application Ser. No. 13/404,272, filed on Feb. 24, 2012;which claims the benefit of U.S. Provisional Patent Application No.61/544,147, filed Oct. 6, 2011 and U.S. Provisional Patent ApplicationNo. 61/446,269, filed Feb. 24, 2011. The disclosures of theseapplications are incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to the art of bag making. Morespecifically, it relates to sealing poly film to create a bag, sealing adrawtape portion of a bag, or sealing a pouch to create a pouch.

BACKGROUND

There are many known bag machines and machines for making bags orpouches. Examples of such machines are described in U.S. Pat. Nos.7,445,590 and 7,326,162, both of which are hereby incorporated byreference. Prior art U.S. Pat. No. 6,452,354 (hereby incorporated byreference) attempted to teach how to make pouches adequate for themedical field. Prior art U.S. Pat. Nos. 5,797,828 and 5,857,953 (both ofwhich are hereby incorporated by reference) relate to inserting andsealing a drawtape into a bag. The prior art machines form a variety oftypes of seals, including hem seals, drawtape seals, side seals, bottomseals, and pouch seals.

One known bag machine is a rotary drum machine. Rotary drum machines arewell known, and detailed descriptions of them may be found in U.S. Pat.Nos. 8,029,428, 6,117,058, 4,934,993, 5,518,559, 5,587,032, and4,642,084 (each of which is hereby incorporated by reference). Bags usedas trash can liners are often formed using such rotary drum bag machine.

The general operation of a rotary bag machine may be seen with respectto FIG. 1. A prior art rotary bag machine 100 continuously processes aweb 201 using a dancer assembly 203, a pair of drum-in rolls 205 and 206(203-206 are part of an input section), a sealing drum 208 (208 is partof a sealing section), a pair of drum-out rolls 210 and 211, a sealingblanket 213, a pair of knife-in rolls 215 and 216, a knife 218 (whichcould be any other web processing device such as a perforator, knife,die cutter, punching station, or folding station), a pair of knife-outrolls 219 and 220 (210-220 are part of an output section), and acontroller 221. Input section, as used herein, includes the portion of abag machine where the web is received, such as an unwind and a dancerassembly. Sealing section, as used herein, includes the portions of themachine that act to impart a seal to the web. Output section, as usedherein, includes assemblies that act on a web downstream of the sealsbeing formed, such as perforators, winders, folders, etc.

The web is provided through dancer assembly 203 to drum 208. Drum 208includes a plurality of seal bars 209. The seals bars are heated andcreate the seals forming the bags from web 201. Web 201 is held againstdrum 208 (and the seals bars) by a Teflon® coated blanket. After web 201leaves drum 208 it is directed to rotary knife 218, which creates aperforation between bags, or could separate adjoining bags. Other priorart machine includes a seal bar on the drum that forms a perforationbetween or beside seals.

Some prior art bag machines include a drawtape section where a drawtapeis inserted into the film. Drawtape sections or machines are typicallyupstream of the rotary drum. Prior art drawtape sections process acollapsed tube with top and bottom layers in surface-to-surface contactwith each other. The tube, web or film and is fed into a drawtapesection where it is slit by a slitting station to form top and bottomweb layers. having respective free edges. The edge regions of the topand bottom layers are separated from each other at a separation station,and the hems are then formed at a hem forming station as continuousdrawtapes are fed to the hem forming stations, and the hems are formedabout the respective drawtapes. The formed hems then pass to hem sealingstations where the edge portions are sealed, typically using hot air,such as linear hot air sealing, for example. Thus, the hem is formed,with a drawtape inserted therein. One prior art drawtape section is theCMD® 1270 GDS bag machine, shown in FIG. 2, and drawtape machine/section250 includes a pair of drawtape unwinds 251 and 252, a draw tape dancer254 (part of the input section), a lower hem sealing belt 256, an upperhem sealing belt 257, a pressure roll 258, a hot air sealer 260, anironing roll 261 a draw tape inserter 262 and a hem folder 263. Themachine of FIG. 1 may be called a bag machine, even though furthersealing is needed to complete the forming of the bag (such as thesealing from the machine of FIG. 1).

While the prior art system of FIG. 2 was a considerable advance overtechnology that predated that design, there is a need for an improveddraw tape machine. For example, seals on bags can fail by immediatecatastrophic failure, where a large portion of the seal fails at once,or from a zipper effect, where the seals are increasingly destroyed,similar to a zipper being unzipped. This can happen, for example, as abag is being pulled from a trash can by the draw string. Prior artdrawtape machines used considerable compressed air and energy to heatthe air to form the seals. Also, at start up it took time for themachine to warm up, to be able to form the seals. The seals either didnot have patterns, and if a pattern would have been used, it would bedifficult to change.

Hot air-based draw tape sections require routine maintenance performedon belts, bearings, heaters, sealing shoes or heat seized parts. Forexample, hem seal belts typically are replaced every 60 days on average.A cost of about $100/belt (there are two hem seal belts), and one hourof labor to change the belts at $50/hour, results in an annual cost of$3000, in addition to 12 hours of downtime a year. Another examplerelates to the hem sealing shoes, which need maintenance because hot airorifices can become obstructed, reducing and altering the air flowpatterns. This will result in inconsistent hem seals and having tocontinually adjust temperatures and air pressure to maintain good seals.This leads to there not being a “standard setting” as the setting variesas the orifices gradually change. Another issue with the sealing shoesis keeping them flat and square to the web for optimal sealing. The hotair sealers necessarily had air blowing on the web or film, which coulddisrupt the web.

A bag machine the forms seals in such a manner that they are less likelyto be destroyed is desired. Also, a machine that has one or more ofreduced maintenance, reduced energy use, reduced use of compressed air,easy to change seal patterns, reduced web disturbance, or reduced filmuse is desirable.

SUMMARY

According to a first example of the present disclosure, a bag or pouchmachine, or methods for making, include an input section and a sealingsection with a rotary ultrasonic sealer.

The rotary ultrasonic sealer is a hem sealer and the sealing sectionfurther includes a hem folder and a drawtape inserter, or the rotaryultrasonic sealer is a side or end sealer, in various embodiments.

The rotary ultrasonic sealer comprises a horn and an anvil, and theanvil has a sealing pattern thereon in another embodiment. The sealingpattern is a continuous sealing pattern, or a discontinuous sealingpattern in various embodiments. The sealing pattern has a cross sectionwith a mostly flat top, and two edges, and the top has a radius at leastat the two edges, and two sides, and/or the two sides are at an angleother than 90 degrees relative to the width in various embodiments.

In various embodiments the sealing pattern includes micro grooves,and/or two rows of offset dots, and/or the top of the pattern has aradius, and/or at least one repeating shape, such as an angled oblong.The repeating shape can change orientation.

Other principal features and advantages will become apparent to thoseskilled in the art upon review of the following drawings, the detaileddescription, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a prior art bag machine;

FIG. 2 is a prior art drawtape machine, a CMD® 1270 GDS bag machine thatcan be modified to use the sealing patterns described herein, and/or tohave the ultrasonic sealing as described herein;

FIG. 3 is a draw tape machine in accordance with the present disclosure;

FIGS. 4A-C are diagrams showing a hem seal made in accordance with thepresent disclosure. FIG. 4A depicts a web laying flat, FIG. 4B depictsthe web as a J-Fold with a drawtape in a hem pocket, and FIG. 4C depictsan end view of ultrasonic sealer with an ultrasonic sealing horn and ananvil that cooperate to form a seal.

FIG. 5 is a rotary ultrasonic sealer (bonder) in accordance with thepresent disclosure;

FIG. 6A depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 6B depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 6C depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 7 depicts an example sealing pattern in accordance with the presentdisclosure;

FIG. 8A depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 8B depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 9A depicts a portion of a bag with a seal pattern made inaccordance with the present disclosure;

FIG. 9B depicts a portion of a bag with a seal pattern made inaccordance with the present disclosure;

FIG. 9C depicts a portion of a bag with a seal pattern made inaccordance with the present disclosure;

FIG. 10A depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 10B depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 10C depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 11A depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 11B depicts an example sealing pattern in accordance with thepresent disclosure;

FIG. 12A depicts a side view of an example anvil in accordance with thepresent disclosure;

FIG. 12B depicts an end view of an example anvil in accordance with thepresent disclosure;

FIG. 12C depicts a cross sectional view of an example anvil inaccordance with the present disclosure;

FIG. 12D depicts an enlarged view of the anvil of FIG. 12C within line12D-12D on FIG. 12C;

FIG. 12E depicts a perspective view of an example anvil in accordancewith the present disclosure;

FIG. 13A depicts a side view of an example anvil in accordance with thepresent disclosure;

FIG. 13B depicts an end view of an example anvil in accordance with thepresent disclosure;

FIG. 13C depicts a cross sectional view of an example anvil inaccordance with the present disclosure;

FIG. 13D depicts an enlarged view of the anvil of FIG. 13C within line13D-13D on FIG. 13C;

FIG. 13E depicts a perspective view of an example anvil in accordancewith the present disclosure;

FIG. 13F depicts an enlarged view of the anvil of FIG. 13B within line13F-13F on FIG. 13B;

FIG. 14 depicts an example sealing wheel and pattern in accordance withthe present disclosure.

Before explaining at least one embodiment of the invention in detail itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting.

DETAILED DESCRIPTION

While the examples described in the present disclosure will beillustrated with reference to particular bag machine design andpatterns, it should be understood at the outset that the example of thepresent disclosure can also be implemented with other machines, andother patterns. Moreover, the various features described below can beused individually, or in any combination thereof.

This present disclosure relates to bag machines, and to forming sealssuch as the seals formed in U.S. Pat. Nos. 7,445,590, 7,326,162,6,452,354, 5,797,828 and 5,857,953. This present disclosure particularlyrelates to the way the seals are formed, and patterns used to form sealsincluding hem seals, drawtape seals, side seals, bottom seals, pouchseals, and other seals made on pouch and bag machines such as thosedescribed above. The present disclosure provides that the hot airsealers of the prior art are replaced with ultrasonic sealers having ahorn and an anvil.

One embodiment provides that it be implemented on a drawtape machine,such as the CMD® 1270 GDS bag machine of FIG. 2. The prior art machinecan be modified to use the sealing methods and patterns describedherein, and/or to have the ultrasonic sealing as described herein. Theanvil of the ultrasonic sealer or heater has a pattern chosen for aparticular purpose. For example, the pattern might be selected toprovide a better seal for a particular type or thickness web, and/ormight have a bag maker's name embossed into the pattern. The anvil canbe changed relatively easily, for example when a different type orthickness of film is being used, and a different pattern produces abetter result.

FIG. 3 shows a drawtape bag machine 300, including the drawtape unwinds251 and 252, draw tape dancer 254, ironing roll 261, draw tape inserter262 and hem folder 263. However, the hot air sealing components havebeen replaced by a rotary ultrasonic sealer 301 (described in moredetail below).

Generally, when implementing the examples of the present disclosure toseals hem seals as shown in FIG. 3, the process includes sealing thedrawtape in the hem area of a bag. The web is run through a series offolding plates and folded over itself creating a “J” folded web (as isdone in the prior art). FIGS. 4A-4C show the making of a hem seal inaccordance with the preferred embodiment. FIG. 4A shows web 201 layingflat. FIG. 4B shows the web as a J-Fold 402 with a drawtape 401 in a hempocket 403. FIG. 4C shows an end view of ultrasonic sealer 301 with anultrasonic sealing horn 405 and an anvil 406 that cooperate to form aseal 407. As the fold is created, drawtape is inserted into to thefolded area. This can be done in accordance with the prior art. Afterthe folding has been completed (and what will become the hem is formed)and the drawtape inserted, the film is sealed, completing the hem, toretain the drawtape in the hem pocket. This seal may be a continuous orintermittent seal. Typically the drawtape may be 1″ wide and the pocket1.5″ wide to allow the tape to slide or draw up when the bag is beingtied. These dimensions may vary depending on the product.

Vibration of sealing horn 405 against anvil 407 imparts energy thatcreates seal 407. As will be discussed below, a pattern on anvil 407 canbe particularly suited for a particular web. The pattern can also havecharacters, figures, etc., that can be used to show trade names, etc.The anvil can be changed when a different pattern is desired. As can beseen in FIG. 3, ultrasonic sealer 301 eliminates the need for thecomponents of the machine of FIG. 2 that require the most frequentmaintenance, particularly those related to hot air sealer 260.

Horn 405 and anvil 406 can be run in contact or at a fixed gap. The hornand the anvil are preferably driven by servo motors, or other types ofmotors. They are coupled, but can be individually driven, or controlledtogether. The preferred embodiment provides that anvil 406 be driven bya Allen Bradley MPM-115 motor. Horn 405 is slave driven from anvil 406via gears. Anvil 406 can be made such that continuous sealing of the hemis possible at a wide range of speeds and with various materials. Theanvil may have any number of patterns producing continuous orintermittent seals.

The preferred embodiment sets the bonder speed (the speed of rotaryultrasound sealer 301) equal to the machine speed. Alternatives providefor the bonder speed to be machine speed +/−5%. The preferred machinespeed is 700-750 feet per minute (fpm). The preferred embodimentprovides that the gap between horn 405 and anvil 406 be zero, andalternatives provide for a fixed non-zero gap. The nip pressure ispreferably between 15-45 PSI at the nip point, but can vary depending onspeed, power level and film thickness. The preferred embodiment uses a600 watt power supply for horn 405 run at a range of 140-180 watts, andcan vary with speed and film thickness.

FIG. 5 shows one embodiment rotary ultrasonic sealer (bonder) 301,including horn 405, anvil 406, a fan 501, a motor 502 and gears 503.This embodiment provides that anvil 406 is driven, and horn 405 isslaved via gears 503 to anvil 406. Alternative embodiments provide thatboth horn 405 and anvil 406 are driven, or that horn 405 is driven andanvil 406 is slaved to horn 405.

As stated above, anvil 406 can have a pattern thereon chosen for theparticular application. FIGS. 6A-6C show various patterns that have beentested. The pattern of FIG. 6A is comprised of an angled (relative tothe direction of the web) seal pattern. The lines forming the patternare a raised pattern on the surface of anvil 406, and the film is sealedin the locations of the raised pattern. Thus, the patterns shown areboth on the anvil, and as appear on the film. The pattern of FIG. 6B isa series of circles or dots, and the pattern of FIG. 6C is a series ofoblongs alternating with circles. The anvil may have raised areas to aidin sealing, cutting or producing a desired pattern. The patterns in FIG.6, as well as other patterns discussed herein, include repeating shapes.The pattern of FIG. 6C includes repeating shapes with changingorientations.

The pattern can be chosen to reduce the zipper effect and/orcatastrophic failure that sometimes occurs in seals made in accordancewith the prior art. The pattern can provide increasing strength in adesired location, such as increasing strength across a hem. The strengthprofile can be affected by dot density, shape, orientation, thickness,etc. of the melted film. One embodiment provides for a greater strengthon the outer edge of the hem than on the inner (toward the bottom of abag for a drawtape garbage bag).

The examples of the present disclosure are not limited to specific sealpatterns, and one aspect of the an example of the present disclosure ischoosing a seal pattern for a particular application or for a group ofapplications. The pattern can be chosen from those disclosed herein, orchosen by testing other patterns. The inventors have learned thatcertain features are more likely to provide seals with desirablestrength profiles, including rounding the edges of the shapes of apattern, having a radius for the pattern, breaking up or offsetting theworking side of the seal, interrupted patterns and symmetrical designs.Patterns with round edges tend to result in stronger seals and a wideroperating window. A domed anvil (providing a radius to the pattern)tends to reduces zippering and widen the operating window. Breaking upor offsetting the working side of the seal tends to reduce or eliminatezippering along the seal. Interrupted patterns often provide wideroperating windows and produce consistent seals. Symmetrical designseliminates the chance of an anvil being installed backwards. Theinventors have also learned that the following tends to result in moredesirable seals: radius all edges of pins/shapes, insure the pattern hasconstant and consistent contact with horn, overall patterns that arecrowned, crowing each pin/shape, hollow tipped patterns, a desirablepattern width, and altering heights of pins/shapes.

FIGS. 7-11 show various seal patterns. FIG. 7 shows a series of pins ordots 701 at 90 degrees. They could be angled at 60 degrees. FIG. 8Ashows a pattern called bats and bananas, with bat shapes 801 and bananashapes 802, with bats 801 shown at about 60 degrees. Alternativesprovide for other angles, such as 60-40 degrees, or a variety of angles.FIG. 8B shows a pattern called bats and Ys, with bat shapes 901 and Yshapes 902, with bat shapes 901 shown at about 60 degrees. Alternativesprovide for other angles, such as 60-40 degrees, or a variety of angles.FIGS. 9A-9C shows bags made in accordance with the present disclosure,where each bag has a fold line 901, 902 or 903, and drawtape 904, 905 or906. The seal patterns can be seen on the bag. FIGS. 10A-C show patternscalled horizontal bananas, vertical bananas, and diamonds. Alternativesprovide for inverting the diamond pattern (sealing the unsealed area andvisa versa), or changing the angles of the diamonds or banana shapes.FIGS. 11A and 11B show patterns that have a steep or shallow sine waveseal. There can be patterns within the sine wave, such as those aspatterns 1101 and 1102.

FIGS. 12A-E show various views of anvil 406. FIG. 12A shows a side viewof anvil 406, and FIG. 12B shows an end view with pattern 1201 visible.FIG. 12C shows a cross sectional view taken along B-B of FIG. 12A. FIG.12D shows the detail of area A of FIG. 12C. FIG. 12E shows a perspectiveview of anvil 406. The pattern on anvil 406 is a continuous line seal,line, where the pattern has sides angled at 45 degrees. Anvil 405 is 4.5inches in diameter, with the pattern being about raised about 0.0225inches, and the width of the anvil is one inch, and the width of theflat portion of the pattern is about 0.025 inches. Alternativeembodiments provide for other dimensions. For example, a pattern widthof 0.035-0.045 inches, 0.055 inches, 0.070 inches, 0.080 inches, 0.190inches, or other dimensions, including changing the angle, height,interrupting the pattern, etc. The preferred embodiment provides for acontinuous pattern (such as shown in FIG. 12) having a width of0.035-0.045 inches. When using the continuous pattern, a radius can beprovided on each side in order to eliminate a sharp edge that may cutthe film. The 0.190 inch continuous pattern has been operated with apower supply of at least 600 watts and stable at speeds of 750 fpm.

The inventors have tested continuous patterns with widths from 0.090inches to 0.025 inches, in increments of 0.005 inches increments. Widthsof about 0.040 inches provided seals that were 90% as strong as the filmitself. Widths as low as 0.025″ wide provided acceptable seals, but lifeof the anvil was shortened, unless it was hardened.

Micro grooves are used in an alternative embodiment. Micro groovingcould have the performance of a solid seal but with a larger operatingwindow and increased power supply stability, simulating the interruptedpattern. Micro grooving includes making a pattern that may be veryshallow such as 0.0005″, maybe less or maybe more. The micro groovingmay be so shallow that it may not be visible to the naked eye. This mayconsist of a groove or any pattern in the sealing surface. The micropattern may be less than the depth of the film thickness. Anotheralternative is an interrupted pattern. Interrupted patterns can be morestable and have a larger operating window when running.

FIGS. 13A-13F show a repeating pattern consisting of two offset dots,cones or pins 1301 and 1302 on an anvil 406A. FIG. 13A shows a side viewof anvil 406 a, and FIG. 13B shows an end view with the pattern. FIG.13C shows a cross sectional view taken along B-B of FIG. 13A. FIG. 13Dshows the detail of area C of FIG. 13C. FIG. 13E shows a perspectiveview of anvil 406A. FIG. 13F shows the detail of area A on FIG. 13B. Thedots of the pattern are preferably cones with a 30 degree angle and0.080 inches wide at the top, and two rows of 106 cones spaced evenlyaround the anvil (the anvil is the same size as that of FIG. 12).Alternatives provide for other dimensions, number of cones, rows ofcones, cones across a greater width of the hem, etc.

The two dot pattern of FIG. 13 is two rows of dots staggered to providecontinuous contact with the horn, to prevent the horn from bouncing andcreating inconsistent seals. The two dot pattern has a radius on theouter edge of each dot that is larger than radius around the inside ofthe dot to relieve the stress concentrations when performing the peeltest and also compensate for any misalignment. The sealing surface ofthe dots should not be rough or uneven, because this could cause poorseals. One pattern has an average of 0.067 inches seal contact. Otherpatterns may have less seal contact area.

FIG. 14 shows an alternative pattern, where just the detail areacorresponding to area A on FIG. 13B is shown. The pattern is a repeatline 1401, at an angle of 60 degrees, with sides angled at 45 degrees,and the width is about 0.157 (including the angled sides). The lines areevenly spaced about the anvil with 236 total lines (about every 0.0599inches). The lines can be long enough to fill most of the width of theanvil. Alternatives provide for other dimensions, or other patterns,including those discussed above. Another embodiment uses a laserengraved cross angle pattern. Other embodiments provide for a non-rotaryultrasonic sealer.

The patterns of FIGS. 13 and 14 are interrupted patterns (i.e., notcontinuous). Interrupted patterns preferably avoid stress concentrationswhen doing a peel test which result in failure and can be more stablewhen running and have a larger operating window.

Alternative embodiments provide that the disclosure be used to sealmultiple webs together, and or used to cut or perforate singe ormultiple webs. It may be used for pouches or end seals or side sealssuch as the seals described in U.S. Pat. No. 8,029,428. When using itfor end or side seals, the ultrasonic sealer can traverse across the webat an angle, such that its machine direction speed matches the webspeed. The pattern can include a center portion that form a line ofweakness for a perforation or separation. The line of weakness is formedby having a raised pattern where the line of weakness is desired, andcan be discontinuous for a perforation. The rotary ultrasonic sealer canbe moved at a varying speed to create a curved cut, such as a wave-topbag. The ultrasonic sealer may operate in the horizontal, vertical planeor in any orientation. A rotary or non-rotary ultrasonic sealer can alsobe used in a pouch machine, such as those described in the prior art.

A single anvil can include multiple patterns, either in the machinedirection or in the cross direction. This can be particularly useful fortesting patterns, or for a machine that will be used with multiple filmtypes, so that multiple preferred patterns may be used. Also, thepattern or patterns can be on a ring that fits over than anvil, for easeof changing patterns.

The present disclosure provides that start-up of the machine is easierand faster, because the rotary ultrasonic sealer is ready withoutpreheating (prior art hem sealers takes 15 minutes longer than the restof the machine to heat up). Also, less energy is used than when a hotair sealer is used—a 17% electrical energy reduction was found for amodified CMD® 1270 GDS. A rotary ultrasonic hem sealer uses 65%-75% lessenergy than a prior art hot air hem sealer (comparing only the sealer,not the entire machine). The rotary ultrasonic sealer uses very littlecompressed air—76% reduction in pneumatic consumption for a modifiedCMD® 1270 GDS machine. The use of a rotary ultrasonic sealer makes itsimple and easy to change the seal appearance or patterns, and providesthe ability to seal customers name or logo in seal area. Adjustments maybe made from outside of guard while machine is running, and the web orfilm does not have air blowing on it or disturbing it. A drawtapemachine using a rotary ultrasonic sealer can have a smaller footprintthan a prior art machine, and should require lower maintenance, sincethere are no hem seal belts, hem block heaters or heaters clogging withburnt poly. Cooling of the seal is not required when using a rotaryultrasonic sealer, and the seal appearance is more consistent.

A drawtape machine using a rotary ultrasonic sealer can save film,compared to a prior art machine. Because the hem seal is more consistentand less likely to fail it can be made smaller. Reducing the hem by ⅛″results in a film savings equal to about $13,100 per year (assuming 0.9mil film, 600 fpm, operating 355 days per year at 95% uptime and amaterial cost of $0.50 per pound). Greater hem reductions leads togreater savings.

A drawtape machine with a rotary ultrasonic sealer can also operate at afaster line speed than the prior art. The preferred embodiment canoperate at 675 fpm, and even 700-750 fpm. Prior art drawtape machineshave not run over 600 fpm.

Alternative uses for the ultrasonic sealing and/or patterns disclosedherein include cut seal applications, slit sealing, die cutting, sidesealing, bottom sealing, cross sealing on a pouch machine, longitudinalsealing on a pouch machine, zipper sealing, spot/stitch sealing (ineither direction, but preferably in the machine direction), pattern/logosealing (in either direction, but preferably in the cross direction),sealing of temperature sensitive materials that would melt usingconventional heating technologies, and perforating a substrate or a web,creating a line of weakness in a web, such as described in U.S. Pat. No.7,445,590 or 7,326,162. Other alternatives provide for using anon-rotary ultrasonic sealer to form seals.

One embodiment provides that the power supply adjusts its output tocompensate for variations in run conditions. Setting the power supply toprovide a percentage of maximum power (and having amplitude feedback)causes the amplitude of the ultrasonic motion to be adjusted. The powersupply will adjust power (watts) very rapidly to maintain continuousamplitude. It will do this to compensate for variations in the runconditions such as pattern seal contact not consistent, film thicknessvariations, wrinkles in the film or pressure variations of the contactbetween the horn and anvil. The control loop should be such thatinstability does not result. Another embodiment provides for aconsistent wattage from the power supply, rather than a constantamplitude. This can be done using a control loop with power, or currentand voltage as feedback and controlled parameters.

Numerous modifications may be made to the different examples describedherein still fall within the intended scope hereof. Thus, it should beapparent that there has been provided in accordance with the presentdisclosure a method and apparatus for a bag or pouch machine and/or anultrasonic sealer and/or sealing patterns that fully satisfies theobjectives and advantages set forth above. Although the invention hasbeen described in conjunction with specific embodiments thereof, it isevident that many alternatives, modifications and variations will beapparent to those skilled in the art. Accordingly, it is intended toembrace all such alternatives, modifications and variations that fallwithin the spirit and broad scope of the appended claims.

What is claimed is:
 1. A machine for creating bags from a web, themachine comprising: an input section configured to receive the web; anda sealing section configured to impart a seal to the web, wherein thesealing section includes a rotary ultrasonic sealer having a rotatinganvil and a rotating horn; wherein the rotary ultrasonic sealer isconfigured to seal at least a portion of the web to itself to therebycreate the seal that at least partially forms a bag; and wherein theanvil has a sealing pattern with a rounded edge.
 2. The machineaccording to claim 1, wherein the anvil has an anvil surface thatextends around the anvil, and wherein a sealing pattern is raisedrelative to anvil surface.
 3. The machine according to claim 2, whereinthe sealing pattern has a sealing surface and a side that extendsbetween the anvil surface and the sealing surface, and wherein the sidehas a rounded end that forms the rounded edge.
 4. The machine accordingto claim 2, wherein the sealing pattern has a sealing surface and a sidethat extends between the anvil surface and the sealing surface, andwherein the side has a radius that forms the rounded edge.
 5. Themachine according to claim 4, wherein the side is angled 45.0 degreesrelative to anvil surface.
 6. A machine for creating bags from a web,the machine comprising: an input section configured to receive the web;and a sealing section configured to impart a seal to the web, whereinthe sealing section includes a rotary ultrasonic sealer having arotating anvil and a rotating horn; wherein the rotary ultrasonic sealeris configured to seal at least a portion of the web to itself to therebycreate the seal that at least partially forms a bag; and wherein theanvil has a sealing pattern with a dot having a rounded edge.
 7. Themachine according to claim 6, wherein the dot is a truncated cone. 8.The machine according to claim 7, wherein the truncated cone is one of aplurality of truncated cones spaced apart along the anvil.
 9. Themachine according to claim 8, wherein the truncated cones in theplurality of truncated cones are arranged in two rows around the anvil.10. The machine according to claim 9, wherein the truncated cones in oneof the two rows are staggered relative to the truncated cones in theother row.
 11. The machine according to claim 6, wherein the anvil has awidth extending between two opposing anvil edges, and wherein therounded edge of the truncated cone faces one of the anvil edges.
 12. Amethod for creating bags from a web, the method comprising: a feedingthe web to a sealing section; and sealing the web by applying ultrasonicenergy using a sealing pattern that includes a rounded edge.
 13. Themethod according to claim 12, wherein applying ultrasonic energyincludes rotating an anvil with the sealing pattern thereon and rotatinga horn.
 14. The method according to claim 13, wherein the anvil has ananvil surface that extends around the anvil, and wherein the sealingpattern is raised relative to anvil surface.
 15. The method according toclaim 14, wherein the sealing pattern has a sealing surface and a sidethat extends between the anvil surface and the sealing surface, andwherein the side has a rounded end that forms the rounded edge.
 16. Themethod according to claim 12, wherein the sealing pattern has a dot withthe rounded edge; wherein the anvil has an anvil surface that extendsaround the anvil; and wherein the dot is raised relative to anvilsurface.
 17. The method according to claim 16, wherein the dot is atruncated cone.
 18. The method according to claim 17, wherein thetruncated cone is one of a plurality of truncated cones spaced apartalong the anvil.
 19. The method according to claim 18, wherein thetruncated cones in the plurality of truncated cones are arranged in tworows around the anvil, and wherein the truncated cones in one of the tworows are staggered relative to the truncated cones in the other row. 20.The method according to claim 17, wherein the anvil has a widthextending between two anvil edges, and wherein the rounded edge of thetruncated cone faces one of the anvil edges.
 21. A machine for creatingbags from a web, the machine comprising: an input section configured toreceive the web; and a sealing section configured to impart a seal tothe web, wherein the sealing section includes a rotary ultrasonic sealerhaving a rotating anvil, a rotating horn, and a sealing pattern with arounded edge, wherein the rotary ultrasonic sealer is configured to sealat least a portion of the web to itself to thereby create a seal that atleast partially forms a bag.
 22. The machine according to claim 21,wherein the sealing surface is on the anvil, and wherein the sealingpattern is raised relative to an anvil surface of the anvil.
 23. Themachine according to claim 21, wherein the sealing pattern has a sealingsurface and a side that extends between the anvil surface and thesealing surface, and wherein the side has a rounded end that forms therounded edge.